In an image capturing apparatus, brightness of a captured image can be controlled by adjusting an exposure amount of an image capturing device such as CMOS (Complementary Metal Oxide Semiconductor), CCD (Charge Coupled Device) with a control of a diaphragm and a shutter speed. However, when a backlight scene having a relatively great brightness difference is captured, there may be generated clipped whites caused by exposure saturation and crushed shadows caused by insufficient exposure due to an insufficient dynamic range of the image capturing device.
There is a known technology that prevents the clipped whites and the crushed shadows due to the insufficient dynamic range. For example, Patent Document 1 discloses a technology that a captured image having a wide dynamic range with no clipped whites and crushed shadows is acquired by exposing twice an image capturing device for different exposure times in a unit period (1 field period= 1/60 sec), and synthesizing two exposure image signals by signal processing. However, some problems have been pointed out in the known technology.    [Patent Document 1] Japanese Patent Application Laid-open No. 2011-176880